Logging tools are used to log various hydrocarbon well measurements during drilling of the well, during completion of the well, and during production of hydrocarbons by the well. Measurements often relate to wellbore conditions and characteristics of the formation surrounding the wellbore. A wide array of logging tools are used to obtain these measurements. Logging tools include a variety of sensors, actuators, telemetry devices, and other suitable measuring devices for the particular application. Logging tools may evaluate the effectiveness of a gravel pack including determining the location and presence of any voids.